The following pedigree shows how the gene for colourblindness was passed in a family for three generations. The gene for colour blindness is sex linked.
![BioF4et121p2q2](https://www.easyelimu.com/images/form_4_past_papers/Form4_EndTerm1_2021/bio_paper_1_2_3/BioF4et121p2q2.JPG)
- Define the term sex linkage.
- Write down the genotype of the parents A and B.
- Write down the phenotypic ratios of the 2nd generation from parents A and B. Show how you arrived at your answer.